HiRise, The Earth and Moon as Seen from Mars (PSP_005558_9040):

“This is an image of Earth and the Moon, acquired at 5:20 a.m. MST on 3 October 2007, at a range of 142 million kilometers, which gives the HiRISE image a scale of 142 km/pixel and an Earth diameter of about 90 pixels and a Moon diameter of 24 pixels. The phase angle is 98 degrees, which means that less than half of the disks of the Earth and Moon have direct illumination. We could image Earth/Moon at full disk illumination only when they are on the opposite side of the sun from Mars, but then the range would be much greater and the image would show less detail.”

“During the simulation, men and women “Martianauts,” as you might call them, will watch Earth disappear into the blackness of space as they munch on the same kinds of food available on the International Space Station. ESA will even attempt to simulate the 40-minute time delay for radio signals to travel from the craft to Earth and back, as the volunteers work and live in extremely isolated conditions.”